The invention relates to composite metal oxide powders. More particularly, the invention relates to highly uniform, nanoscale composite metal oxide particles, such as lithiated manganese oxide, produced by laser pyrolysis.
Manganese can exist in various oxidation states. Correspondingly, manganese oxides are known to exist with various stoichiometries. In addition, manganese oxides with a particular stoichiometry can have various crystalline lattices, or they can be amorphous. Thus, manganese oxides exhibit an extraordinarily rich phase diagram. Various crystalline forms of manganese oxide, as well as other metal oxides, can accommodate lithium atoms and/or ions into its lattice.
The ability of metal oxide, such as manganese oxide, to intercalate lithium can be used advantageously for the production of lithium and lithium ion batteries. In particular, LixMn2O4, 0 less than x less than 2 can be used in the formation of cathodes for secondary batteries, i.e., rechargeable batteries. These are referred to as xe2x80x9crocking-chairxe2x80x9d batteries by their ability to reversibly vary x between certain values as the battery charges or discharges. The lithiated manganese oxides can have a variety of crystal structures. Because of the interest in lithiated manganese oxides and other composite metal oxides, there is considerable interest in developing better approaches for producing composite metal oxides, such as lithiated manganese oxide.
In a first aspect, the invention pertains to a method of producing a composite metal oxide particles, the method comprising reacting an aerosol to form a powder of composite metal oxide particles with an average diameter less than about one micron, the aerosol comprising a first metal compound precursor and a second metal compound precursor.
In a further aspect, the invention pertains to a method for producing lithium metal oxide, the method comprising pyrolyzing a reactant stream in a reaction chamber, the reactant stream comprising a lithium precursor, a non-lithium metal precursor, an oxidizing agent, and an infrared absorber, where the pyrolysis is driven by heat absorbed from a light beam.